Step 1: Prepare the glass noodles by soaking them in warm water for 10 minutes, then drain and chop them into 1-inch pieces.
Step 2: Heat a tablespoon of oil in a large skillet or wok over medium-high heat. Add garlic and ginger, sautéing for 30 seconds until fragrant.
Step 3: Add the ground pork or shrimp to the skillet and cook until fully browned and crumbled.
Step 4: Toss in the cabbage, carrots, and glass noodles. Stir-fry for 2-3 minutes until the vegetables are slightly softened but still retain some crunch.
Step 5: Stir in the soy sauce, oyster sauce, sesame oil, and sugar. Mix well and cook for another minute.
Step 6: Spread the filling on a large baking sheet and let it cool completely. This is a vital step to prevent the wrappers from tearing.
Step 7: Place one spring roll wrapper in a diamond shape. Add 2 tablespoons of filling near the bottom corner.
Step 8: Lift the bottom corner over the filling, tucking it under slightly, then fold the left and right corners toward the center. Roll tightly toward the top corner.
Step 9: Brush the top corner with the cornstarch slurry and press firmly to seal the roll.
Step 10: Heat oil in a deep pan to 350°F. Fry the rolls in batches for 3-5 minutes until golden brown and crispy. Drain on paper towels before serving.